It is easy and most of it comes down to what happens in the penalty box - a player takes a dive and it looks “good enough” then a penalty is given. A player from a non favored side is actually tripped or his shirt pulled in the box “play on”. With such close games can very much make the difference between who wins or who does not!
The team from Cameroon was suspected of collaborating in this scheme. They more or less mailed in their game against Brazil in the qualifying rounds. A savvy bettor might have expected a closer game, after all Brazil had pretty much qualified and Cameroon had played fairly well. Then they allowed Brazil to run up the score on them. I was suspicious of that particular game, and the fixed betting can be on score rather than result, as the betting houses offer odds on number of goals and score lines.
Would imagine that the more meaningful games are more protected. Two reasons, too much national pride on the line, and the players on the bigger teams are making very large salaries playing club football, therefore less open to offers. When you check out where some of the lesser team players are employed and what they make, you can see why there’s an opening for this sort of fixing.
And it probably isn’t confined to soccer. Some of these syndicates would not be above putting pressure on players by threatening their families. This could apply in NHL hockey for example with various players from eastern Europe. Ever notice how they often underperform in the playoffs?